Waning Immune Humoral Response to BNT162b2 Covid-19 Vaccine over 6 Months

Despite high vaccine coverage and effectiveness, the incidence of symptomatic
infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has
been increasing in Israel. Whether the increasing incidence of infection is due
to waning immunity after the receipt of two doses of the BNT162b2 vaccine is
unclear.

METHODS
We conducted a 6-month longitudinal prospective study involving vaccinated
health care workers who were tested monthly for the presence of anti-spike IgG
and neutralizing antibodies. Linear mixed models were used to assess the dynamics
of antibody levels and to determine predictors of antibody levels at 6 months.